Selection and operation of liquid nitrogen sample storage systems

Liquid nitrogen (LN₂) storage containers are essential equipment in in vitro fertilization (IVF) centers and biobanks. They enable the long-term preservation of embryos, oocytes, and sperm at ultra-low temperatures (~−196 °C), effectively halting all biochemical activity to “suspend the biological time” of the samples.

These containers are designed with a double-walled metallic structure and a vacuum-insulated space between the layers, which minimizes heat transfer, allowing the LN₂ to evaporate slowly and maintain a stable temperature below −150 °C—the threshold required to prevent sample degradation. LN₂ containers used in IVF are typically vacuum-insulated Dewar vessels, characterized by their lightweight construction, durability, and narrow neck design to reduce evaporative loss.

To ensure safety and optimal performance, technical personnel must be thoroughly trained in proper LN₂ container handling, routine and scheduled refilling procedures, and compliance with relevant standards (e.g., ISO, HFEA guidelines) for cryogenic sample storage.